On 8/22/05, Wolfgang Denk wd@denx.de wrote:
In message OF8ADB0661.25EF292C-ON07257065.00568E7A-07257065.00576B05@mck.us.ray.com you wrote:
I have completed the initial port of U-Boot to a custom PPC405/VirtexII Pro FPGA board and I am starting to look at ways to store the U-Boot environment in the CF card used for FPGA configuration by the Xilinx SystemAce.
Please re-read the archives why this is not as trivial as it may seem.
I am leaning toward the approach of adding DOS FAT write support and adjusting the initial U-Boot environment to provide sufficient stack space
This won't help you much. In the first step, you would have to modify the whole CF and DOS FAT code such that it works while running from flash. This is a non-trivial task, and I don't intend to accept such modifications for inclusion in the publich tree.
Does a system ace CF card have a partition table? Maybe you could make a special partition on the CF for this type of info. You would need a sector read routine and code to parse the partition table to index into the environment sectors. You would probably need some ram available (or at least a bunch of registers) to pull this off.
Another option might be to store the environment stuff as data to be loaded into an accessible block ram on fpga power-up. I haven't looked at how system ace handles this sort of thing. Are the block ram contents stored in separate files on the CF?